Current treatments for alcohol use disorders (AUD) have limited efficacy. A previous 28-day pilot trial of N-acetyl cysteine (NAC) vs placebo found NAC to be feasible and safe, with evidence of improvement on some measures of alcohol consumption. Thus, the primary aim of the NAC-AUD study is to examine the therapeutic and cost-effectiveness of NAC vs placebo in improving treatment outcomes for AUD. We will also examine the (i) effect of NAC vs placebo on mood, markers of liver injury, cognition and hangover symptoms; and (ii) predictors of any response.

This double-blind trial will randomise participants with AUD to a 12-week regimen of either NAC (2400 mg/day) or placebo. All participants will receive medical management. The primary drinking outcome will be the number of heavy drinking days (HDDs) per week, validated by phosphatidylethanol (PEth). Secondary alcohol-related outcomes will include standard drinks per drinking day (SDDD) per week and absence of any HDDs. Other secondary outcomes will include markers of liver injury, depression, anxiety, craving, hangover symptoms, cognition and blood oxidative stress markers. We will also examine the cost-efficacy of NAC vs placebo.

Ethics approval for the study has been granted by The Sydney Local Health District Ethics Review Committee (X21-0342& HREC2021/ETH11614). There are no restrictions on publication from the sponsor or other parties.

NCT05408247.

Emerging research indicates that integrated treatment of co-occurring post-traumatic stress disorder (PTSD) and substance use disorder can be effective among adolescents and young people. However, various barriers exist to young people accessing evidence-based treatments. Telehealth offers an opportunity to address these barriers and provide a scalable and accessible alternative to inperson treatment. This paper describes the study protocol for a randomised controlled trial (RCT) examining the efficacy, safety and cost-effectiveness of an integrated trauma-focused cognitive-behavioural treatment for traumatic stress and substance use among adolescents and young adults (Concurrent Treatment of PTSD and Substance Use Disorders Using Prolonged Exposure – Adolescent and Young Adult version (COPE-A)) when delivered in person compared with via telehealth.

A two-arm, parallel group, single-blind, non-inferiority RCT with follow-up at 4 months and 12 months post study entry will be conducted in Sydney, Australia. Participants (170 adolescents and young adults aged 12–25 years) will be allocated to receive COPE-A either in person or via telehealth (allocation ratio 1:1) using minimisation. Project psychologists will administer treatment via both modes of delivery over a maximum of 16 sessions of 60–90 min. The primary outcome will be between-group differences in change in the severity of PTSD symptoms from baseline to 4-month follow-up, as measured by the Clinician-Administered PTSD Scale for Children and Adolescents for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.

This study has been approved by the Sydney Children’s Hospitals Network Human Research Ethics Committee (2024/ETH01050). Research findings will be published in peer-reviewed journals and presented at scientific conferences.

ACTRN12624000776505.

V.2.3, 20 March 2025.